{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T22:29:49Z","timestamp":1784327389240,"version":"3.55.0"},"reference-count":41,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2021,9,29]],"date-time":"2021-09-29T00:00:00Z","timestamp":1632873600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001700","name":"Ministry of Education, Culture, Sports, Science and Technology","doi-asserted-by":"publisher","award":["18K16396, 16K10631, 19H03740, 19K17603, 19K08585, and 16K109503"],"award-info":[{"award-number":["18K16396, 16K10631, 19H03740, 19K17603, 19K08585, and 16K109503"]}],"id":[{"id":"10.13039\/501100001700","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Public Trust Cardiovascular Research Foundation","award":["2017"],"award-info":[{"award-number":["2017"]}]},{"DOI":"10.13039\/100007449","name":"Takeda Science Foundation","doi-asserted-by":"publisher","award":["2016 and 2020"],"award-info":[{"award-number":["2016 and 2020"]}],"id":[{"id":"10.13039\/100007449","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008667","name":"SENSHIN Medical Research Foundation","doi-asserted-by":"publisher","award":["2016 and 2020"],"award-info":[{"award-number":["2016 and 2020"]}],"id":[{"id":"10.13039\/501100008667","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100013236","name":"MSD Life Science Foundation, Public Interest Incorporated Foundation","doi-asserted-by":"publisher","award":["2016"],"award-info":[{"award-number":["2016"]}],"id":[{"id":"10.13039\/501100013236","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>The characterization of aortic valve interstitial cells (VICs) cultured under optimal conditions is essential for understanding the molecular mechanisms underlying aortic valve stenosis. Here, we propose 2% hypoxia as an optimum VIC culture condition. Leaflets harvested from patients with aortic valve regurgitation were digested using collagenase and VICs were cultured under the 2% hypoxic condition. A significant increase in VIC growth was observed in 2% hypoxia (hypo-VICs), compared to normoxia (normo-VICs). RNA-sequencing revealed that downregulation of oxidative stress-marker genes (such as superoxide dismutase) and upregulation of cell cycle accelerators (such as cyclins) occurred in hypo-VICs. Accumulation of reactive oxygen species was observed in normo-VICs, indicating that low oxygen tension can avoid oxidative stress with cell-cycle arrest. Further mRNA quantifications revealed significant upregulation of several mesenchymal and hematopoietic progenitor markers, including CD34, in hypo-VICs. The stemness of hypo-VICs was confirmed using osteoblast differentiation assays, indicating that hypoxic culture is beneficial for maintaining growth and stemness, as well as for avoiding senescence via oxidative stress. The availability of hypoxic culture was also demonstrated in the molecular screening using proteomics. Therefore, hypoxic culture can be helpful for the identification of therapeutic targets and the evaluation of VIC molecular functions in vitro.<\/jats:p>","DOI":"10.3390\/ijms221910534","type":"journal-article","created":{"date-parts":[[2021,9,30]],"date-time":"2021-09-30T00:03:42Z","timestamp":1632960222000},"page":"10534","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Hypoxic Culture Maintains Cell Growth of the Primary Human Valve Interstitial Cells with Stemness"],"prefix":"10.3390","volume":"22","author":[{"given":"Kaho","family":"Kanno","sequence":"first","affiliation":[{"name":"Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Toon, Shitsukawa, Ehime 791-0295, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomohisa","family":"Sakaue","sequence":"additional","affiliation":[{"name":"Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Toon, Shitsukawa, Ehime 791-0295, Japan"},{"name":"Department of Cell Growth and Tumor Regulation, Proteo-Science Center (PROS), Ehime University, Toon, Shitsukawa, Ehime 791-0295, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mika","family":"Hamaguchi","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Pulmonology, Hypertension, and Nephrology, Ehime University Graduate School of Medicine, Toon, Shitsukawa, Ehime 791-0295, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kenji","family":"Namiguchi","sequence":"additional","affiliation":[{"name":"Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Toon, Shitsukawa, Ehime 791-0295, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daisuke","family":"Nanba","sequence":"additional","affiliation":[{"name":"Department of Stem Cell Biology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8510, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jun","family":"Aono","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Pulmonology, Hypertension, and Nephrology, Ehime University Graduate School of Medicine, Toon, Shitsukawa, Ehime 791-0295, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mie","family":"Kurata","sequence":"additional","affiliation":[{"name":"Department of Pathology, Division of Analytical Pathology, Ehime University Graduate School of Medicine, Toon, Shitsukawa, Ehime 791-0295, Japan"},{"name":"Department of Pathology, Proteo-Science Center (PROS), Toon Shitsukawa, Ehime 791-0295, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0847-0456","authenticated-orcid":false,"given":"Junya","family":"Masumoto","sequence":"additional","affiliation":[{"name":"Department of Pathology, Division of Analytical Pathology, Ehime University Graduate School of Medicine, Toon, Shitsukawa, Ehime 791-0295, Japan"},{"name":"Department of Pathology, Proteo-Science Center (PROS), Toon Shitsukawa, Ehime 791-0295, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shigeki","family":"Higashiyama","sequence":"additional","affiliation":[{"name":"Department of Cell Growth and Tumor Regulation, Proteo-Science Center (PROS), Ehime University, Toon, Shitsukawa, Ehime 791-0295, Japan"},{"name":"Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Shitsukawa, Ehime 791-0295, Japan"},{"name":"Department of Molecular and Cellular Biology, Research Center, Osaka International Cancer Institute, Chuo-ku, Osaka-shi, Osaka 541-8567, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1260-4202","authenticated-orcid":false,"given":"Hironori","family":"Izutani","sequence":"additional","affiliation":[{"name":"Department of Cardiovascular and Thoracic Surgery, Ehime University Graduate School of Medicine, Toon, Shitsukawa, Ehime 791-0295, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,9,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1005","DOI":"10.1016\/S0140-6736(06)69208-8","article-title":"Burden of valvular heart diseases: A population-based study","volume":"368","author":"Nkomo","year":"2006","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2387","DOI":"10.1161\/ATVBAHA.114.302523","article-title":"Calcific aortic valve disease: A consensus summary from the Alliance of Investigators on Calcific Aortic Valve Disease","volume":"34","author":"Yutzey","year":"2014","journal-title":"Arterioscler. 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